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2017 3.7.. what should be my next mod?!

TURTL3

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The SCT tuner (I have one) gives you the option to change the gear ratio - but it doesn't actually do anything, since the '15 and up Mustangs hold this info in the BCM (Body Control Module) and the SCT modified the ECU (Engine Control).

If you have an automatic transmission - the change in gear ratio will need the tune adjusted for shift points. If you already have an aftermarket tune, simply email / call them and request a change. Most of them should be well versed in making the needed changes.

If you want to more about the BCM and the changes you CAN make in there (including gear ratio) with a computer, FORSCan (Free software) and an adapter that lets you access it ($30-50 depending) check out this thread:

https://www.mustang6g.com/forums/showthread.php?t=61773


Tire / wheel size doesn't really matter unless you make drastic changes. It's all about tire diameter.

Also if you make a more drastic gear ration change - from 3.15 to say 3.73 for example - you MIGHT need to make the change in the BCM for gear ratio, as I personally don't know the limitation of the automatic compensation the ABS / Wheel sensors / system is capable of.

Clear as mud?

Keep in mind - there are 15-17 owners out there who THINK the SCT can change gear ratios - like I said it HAS the option (it just doesn't do anything, it's applicable to the older cars) but it does NOT write to the BCM where this info is stored.

Ahh ok I got it now. Having a manual makes all of this just a little easier lol
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ctandc72

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Ah ok, that's what I figured thanks. I ride around on 20in wheels so I stopped caring about my speedo accuracy a long time ago lol Probably going to do 3.55s after Uncle Sam shovels me my tax money. I would do 3.73s but I can't justify the price difference especially coming from 3.15.
The ABS / wheel sensor has a range of adjustment. Odds are your speedo is accurate with 20" wheels.

Besides, it's all about tire diameter - not rim / wheel size.

Quick example:

My '17 V6 started with the OEM wheels / tires

235/55/17 - diameter = 27.2"

I went to 18" GT wheels

235/50/18 - diameter = 27.3"

Then finally I went to 19x10 SVE S350 wheels

275/40/19 - diameter = 27.7"

All those sizes are well within a range where the ABS / Wheel sensor reads revolutions of the tire and adjusts the speedo accordingly - as it does with a gear change from say 3.15 to 3.55.

I GPS verified my speedo when I went from 235/55/17 to 235/50/18. Then the same when I added 3.55 gears. Then again when I added the 19" wheels. It was dead on every time.
 

TURTL3

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The ABS / wheel sensor has a range of adjustment. Odds are your speedo is accurate with 20" wheels.

Besides, it's all about tire diameter - not rim / wheel size.

Quick example:

My '17 V6 started with the OEM wheels / tires

235/55/17 - diameter = 27.2"

I went to 18" GT wheels

235/50/18 - diameter = 27.3"

Then finally I went to 19x10 SVE S350 wheels

275/40/19 - diameter = 27.7"

All those sizes are well within a range where the ABS / Wheel sensor reads revolutions of the tire and adjusts the speedo accordingly - as it does with a gear change from say 3.15 to 3.55.

I GPS verified my speedo when I went from 235/55/17 to 235/50/18. Then the same when I added 3.55 gears. Then again when I added the 19" wheels. It was dead on every time.
Makes sense. I never verified it but it always seemed correct so I never really gave it much thought. I'm 20x9 squared now. I may do a staggered set with summer tires. The 9 inch wheels up front introduce a bit of under steer compared to the thinner 7in (I think) stock ones, but I've gotten used to it.

I might be done after I get the 3.55s on. After Roush exhuast, wheels, MPT Tune, heavy weight shift knob and some cosmetic stuff, I'm pretty happy with her, except for wanting the shorter gears.

I can't really justify FI in these cars when the kits are so expensive and the reason why I went with the V6 was to have a NA car and enjoy that linear curve and nice exhaust roar.

I thought about maybe getting the shifter replaced but the reviews forSteeda and MGW options are mixed. Not worth the money imo. My MT 82 has broken in nicely and I've learned to live with its quirks.

Thanks for the help. I'm on the hunt for gears. I have shelby auctions on ebay and I search around periodically. I can't wait to get those on because I think it'll be the cherry on top.

Hands down the MPT tune has been the best money I've spent on her. Such a great product.
 

DANA44

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I ended up spending $20 for Energy Suspension 4-1134G Shifter Bushing.
The improvement with the stock shifter was go enough for me and noticeable.
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